At present, customers with an iPad or such a tablet computer expect to surf the Internet and shop on line whenever and wherever possible, however, a portion of the existing tablets don't have cellular support, while the tablets with cellular support are relatively more expensive. In terms of the customers that have purchased a tablet without cellular support, it is anyway inconvenient to carry a wireless router along when they are out of home, and the router is likely to get lost. Meanwhile, many customers who have purchased a tablet would in addition buy a protective case, in order to protect their tablets from being scratched or damaged.